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A 

E  E  P  O  R  T 

'>X  TIIK. 

i;XTENT  AND  CHARACTER  OF  TIIK  J)ISTI!ICT 
SUPl'LYLNG  AVATER 

TO  THK 

CITY   OF  BIlOOKLY:Nr. 

BV 

THEODOEE  AVESTON,  C.  E. 

WITH  A 

COMMUNICATION  IN  RELATION  TO  THE  SAME, 

FKCI.M 

JAMES  P.  IvlKKAVOOD,  ESQ. 

ENGINEER  OF  THE  WORKS. 

\M>  AN' 

ANALYSIS  OF  THE  WATKil  OF  THK  JAMAICA  KFSERVOIU, 

Hy  Vkov.  a   K.  KATUN,  Cukmist. 


li  n  ( » ( >  K  L  Y  N  .    N  ^• 
1801. 


D  .    VA  N    NOSTRA  N  D  , 
PUBLISHER. 


K  E  P  O  E  T 


^roohlnn  ^o;ub  of  (i'clliitcr  (Tommissionci-s, 
May  10th,  18G0. 

A  coMMTXTCATrox  was  received  from  the  C'liief 
Eiigineei',  ^vitll  a  inaj)  of  tlie  drainage  area  of  tlie 
streams  fi'oiii  Avliicli  the  su])])ly  of  the  eity  is  now 
arranged  to  he  procured,  together  a\  ith  t\vo  slieets 
of  ])rofik^s^  showing  certain  characteristics  of  the 
great  water  reservoir  under  the  Hempstead  Phiins, 
and  a  i'e])ort  from  Mr.  T.  AVeston,  explanatory  of 
this  drainage  ;  also  a  re])ort  from  Professor  A.  K. 
Eaton,  shoAving  a  gradual  inipi'ovenieiit  of  the  cliai*- 
actt'r  of  the  water  of  Jamaica  Pond  duiiiiLi"  tlic  tiist 
season,  cVrc 

Referred  to  Messrs.  I>revoort  and  I^rn^li,  w  itli 
the  ])oW('i'  to  piint. 


6 


EncxIxeer's  Office,  May  9fh,  1860. 

WiLLiA:\r  Wall,  Esq., 

Vice-President^  dr. 

SiE : — I  sul^mit  lierewitli  a  map  of  tlie  drainage 
area  or  water-slied  of  tlie  streams  from  wliicli  tlie 
supply  of  tlie  city  of  Brooklyn  is  now  arranged  to 
l)e  procured,  together  witli  profiles,  showing  certain 
characteristics  of  the  great  water  reservoir  under 
the  Hempstead  Plains,  and  an  interesting  report 
from  Mr.  Weston,  explanatory  of  this  drainage. 

In  a  note  to  my  rej^ort  on  the  gaugings  of  the 
different  supplying  streams  (Januar}^,  1 858),  I  esti- 
mated, from  th(*  map  of  Long  Island,  the  drainage 
area  referred  to  as  comprising  al)()ut  thirty-four 
square  miles. 

The  old  map  of  Long  Island,  from  which  I  made 
this  measurement,  was  too  general  and  indefinite  in 
its  character  to  furnish  correct  results  of  this  kind ; 
I  therefore  directed  Mr.  Weston,  last  Fall,  to  take 
advantage  of  the  leisure  which  the  stoppage  of  the 
mason- work  on  the  conduit  presented,  to  obtain  a 
correct  outline  of  the  drainage-l)asin.  To  this  he 
applied  the  conduit  parties  in  December  last,  and 
the  service  has  been  j^erformed  by  all  concerned 
very  satisfactorily. 


7 


Instead  of  .'U  s<[uar('  iiiiks  of  av.iilaldc  waliT- 
slu'd,  as  I  lia'l  sii])posc'(l  lV<»iii  the  <>1<1  iii;i]>,  tlir 
correct  survey  sliows  an  aggregate  of  r.oj  s(juai-c 
miles  connected  \\itli  tlie  streams  ai-c  ii<»\v 

])re])arcd  for  use,  and  1  :>  s(|uare  uiiles  of  una}>j»lied 
drainage  area,  l>e](»nging  to  Springiield  Pond,  and 
various  small  streams  not  availaMe  foi*  pondage. 

Of  tlie  average  annual  rain-l'all  lalling  u[>on  any 
riverd)asin,  a  certain  fraction  finds  its  Avay  int<>  tlie 
channel  (►f  the  stream,  either  diicctly  upon  the  sur- 
face, or  after  ])ercolation  through  the  earth  and 
strata  underneath.  Another  fraction  is  consume(l 
l)y  evaporation  and  vegetation,  and  another  fraction 
finds  its  Avay  to\vards  the  sea  Ly  underground  crev- 
ices and  channels,  and  never  escapes  again  to  the 
surface. 

This  last  fraction  must  he  more  than  usually 
large  on  the  TIem]>stead  Plains  hasin,  \vliere  the 
natural  formation  ])resents  no  rocks  or  cla\'  to  inter- 
cept the  last-descrilxMl  ])nrtion  (►f  tlie  rain-fall  and 
force  it  to  the  surface,  l»ut,  on  the  contiary,  presents 
no  oltstaele  to  il^  descent  seaward  on  the  spaces  (»f 
ground  intervening  hetwcen  the  various  \  alleys, 
e.\ce]>t  the  friction  of  the  particles  of  sand,  f  )und  in 
this  case  to  he  e(jual  to  a  late  of  descent  ot*  \'2  feet 
to  the  mile. 

Jt  has  long  a])peare(l  to  me  that  much  of  this 


8 


last  portion  of  the  reservoir  water  might  he  inter- 
cepted hy  underground  drainage ;  hut  it  might 
require  these  drains  to  he  j)laced  so  low  as  to  involve 
pum})ing  to  deliver  the  water  into  the  conduit. 

The  AN^ater  thus  obtained  is  j^ure  and  limpid,  and 
entirely  free  from  the  discoloration  which  attends, 
more  or  less,  the  water  of  the  open  streams.  The 
subject,  at  some  future  time,  will  merit  a  closer 
study. 

The  water  of  some  of  the  streams  is  sometimes 
found  to  l)e  slightly  l)ro^\  n  in  color.  The  Jamaica 
Pond  A\'ater,  Avlien  first  used,  was  at  times  consider- 
ably tinted  in  this  Ava}  ;  it  is  but  little  affected  in 
this  Avay  now,  though  the  evil  can  never,  in  my 
opinion,  l)e  entirely  obviated  luitil  certain  deposits 
of  muck  above  the  pond  are  either  partially 
or  A\liolly  removed.  The  muck  thrown  out  from 
Jamaica  Pond  was,  during  the  first  season,  covered 
in  spots  with  a  Avliite  efflorescence  of  a  bitter  taste  ;  * 
and  a  similar  salt  was  found  deposited  on  the  gravel 
at  the  Avater  s  edge  of  the  u])2)er  end  of  the  pond. 

The  pools  of  standing  Avater  outside  of  the  pond, 
lying  in  contact  AN'ith  the  muck  spoil  banks,  had  the 
same  bitter  taste. 

I  sent,  at  that  time,  specimens  of  the  Avater  of 
the  pond,  draAvn  from  different  points,  and  of  these 
pools,  to  Prof  Eaton,  chemist,  for  examination, 


9 


and  suldiiit  licrcw  itli  liis  i'('|M»rt  t]i('ro(Hi.  His  report 
is  very  satisfactory,  as  showing  a  gradual  inij>r()V('- 
nient  in  the  eliaracter  of  tlie  watei-  of  Jamaica 
Pond  during  the  first  season,  and  a  ])ro])a])ility  that 
the  same  de])tli  of  discoloration  will  not  occur  again. 

To  I'id  all  the  streams  of  the  impui'ities  referre(1 
to,  and  the  tendenc\  to  discoloration  lirowini''  out  of 
the  lai'ge  de])osit  of  muck  in  tlieir  channel-ways, 
will  he  a  work  of  considerahle  time. 

Within  the  limits  of  the  diiferent  su])ply  reser- 
voirs, the  muck  has  heen  entirely  removed;  hut, 
al)<>ve  the  I'eservoirs,  nothing  has  heen  done  as  yet 
to  se|)arate  the  channels  of  the  streams  from  the 
vegetal )le  accumulation  through  which  they  Wow. 

At  Jamaica  J^)nd  the  discoloration  can  he 
readily  traced  to  the  cause  suggested.  AVhen  the 
l)ond  is  draAvn  down  1:2  or  IS  inclies,  so  that  its 
surface  Avater  does  not  correspond  Avith  the  surface 
of  the  hog  or  swamps  ahove,  the  discoloration  all 
hut  ceases  ;  for  the  ra])id  floAV  of  the  water  tlirougli 
a  channel  situated  in  the  muck  deposit  seems  to 
affect  it  hut  little,  com]>ared  with  it^  sIonv  ]>rogress 
there  an  hen  the  surface  of  the  A\  ater  lies  steeping 
o\-er  the  surface  of  the  hosr. 

At  Jamaica  Pond,  the  I'emoval  of  the  muck  on 
Rider's  Creek  \vould  tend  nuich  to  the  improvement 
of  the  water  tliere  ;  and  the  excavation  of  a  Avide 


10 


channel-way  in  the  main  creek  wouhl,  it  is  thought, 
be  of  service  in  the  same  way.  Instead  of  removing 
the  muck  where  the  deposit  is  Lai"ge,  it  may  answer 
the  same  purpose  to  cover  its  surface  with  two  or 
three  feet  of  sand  or  gravel,  enlarging,  at  the  same 
time,  and  straightening  the  channel  of  the  stream. 

This  Avill  prevent  the  water  spreading  over  the 
bottom  as  now,  and  confine  it  to  the  creek  channel. 

Jamaica  Pond  Avater  appears  to  l)e  more  sub- 
ject to  discoloration  than  the  water  of  the  other 
ponds,  arising,  probal>ly,  from  the  fact  that  the 
accumulation  of  vegetable  matter  in  tlie  valley  of 
this  stream  is  nuich  greater  tlian  in  the  valle}'s  of 
the  other  streams  ;  from  which  it  may  be  inferred 
that  this  stream  Avas  ponded  and  used  long  before 
the  other  streams  to  the  east  of  it. 

The  other  j)onds  show  a  l)etter  color  of  water 
than  Jamaica,  and  ^vhen  the  ne^v  conduit  is  fin- 
ished, and  their  waters  can  l)e  brought  down,  they 
will  prol)aT)ly  modiiy^  and  ini])rove  nnich  the  tone  of 
the  present  Av^ater. 

Some  legislation  seems  necessary  to  give  the 
city  the  right  hereafter  to  take  such  action  in  the 
valleys  of  the  streams  as  will  secure  at  all  times 
pure  water,  whether  b}'  mucking  out  those  valleys 
gradually,  or  following  tlie  other  course  suggested 
above. 

JAMES  P.  KIRKWOOD. 


11 


jA:\rEs  P.  KiijKWOOD,  Esq., 

DkaPv  Sik  : — At  your  i"e([iU'st  1  have  nia<l»*  a 
full  analysis  of  tlie  Avater  of  Jamaica  Pond,  tlic 
source  of  tlic  })ivscnt  8Uj)})ly  of  water  to  tlic  city  of 
P)i*o()lvlyn,  and  also  ])artial  analyses  of  tlic  Avatcr  of 
Beaver  Creek,  wliicli  flows  into  tliis  ])ond,  and  of 
that  of  some  pools  outside  the  ])ond,  at  ])oints 
designated  as  stations  19  and  24  (see  sketch). 

The  analysis  of  the  water  from  the  centre  of  the 
pond  gives  the  following  results  in  grains  per  gal- 
lon : — 


.()1)7 
.21  1 

Sodium, ....   

.078 

Phospliatcs   (iron  and 

.:U)9 

Sulphuric  Acid, ,  

.195 

Chloi-iiio,  

.li:i 

Carbonic  Acid,  in  oni- 

.804 

Silica,  

.708 

Organic  flatter,  

1 

4.899 


CoMniNED   AS   FOLLOWS  : 

Carl)<»natc  of  Lime,  998 

Suljdiatc  of  Lime,  882 

Chloride  of  Sodium,.  .  .  .180 
Carbonate  of  Magnesia,  .577 
Piinspliatcs  :    iron  and 

alumina  809 

Silica,  703 

Oi-ganic    matter  and 

lns<   l.-2;i4 

4.899 


Comj»ariiig  tlie^e  results  with  (dlicrs  o]>tained 
from  examination  <d'  tlic  water  a^  taken  from  tlie 


12 


pipes  in  Brooklyn  May  18tli,  1859,  and  again  from 
tlie  pond  Sept.  1st,  1859,  tliere  appears  to  have  heen 
a  decided  improvement  taking  place  in  tlie  quality 
of  tlie  water  up  to  tlie  period  when  tlie  sample  was 
taken,  of  wliicli  tlie  analysis  is  given  above.  This 
was  Dec.  23d,  1859.  This  is  readily  seen  hy  placing 
the  results  together,  as  foUow^s  : — 


Water  of 

Water  of 

Water  of 

May  ISth. 

Sept.  1st. 

Dec.  23d. 

Organic  matter, grains  per  gall., 

8.285 

1.852 

1.234 

Inorganic  matter,  "  " 

5.475 

4.478 

3.165 

Solid  residue,  "  " 

8.760 

6.330 

4.399 

The  impurities  in  the  water  examined  in  May 
were  owing,  no  doul)t,  in  part  to  the  accumulation 
of  foreign  matters  in  tlie  i)ipes  previous  to  the 
distril)ution  of  the  water,  as  the  pipes  were  then 
just  opened.  The  proportion  of  iron  obtained  in 
December  was  much  less  than  in  either  of  the 
preceding  examinations,  and  this  is  a  direct  eifect 
of  the  diminution  of  saline  matters  in  tlie  pond 
water,  the  character  and  source  of  Avhich  will  l)e 
noted  below. 

The  next  examination  is  of  tlie  water  of  Beaver 
Creek,  a  swift-running  stream,  which  is  tlie  chief 
source  of  supply  of  the  pond.    This  })roves  to  be  a 


1  :\ 

])Uivi'  water  than  tliat  of  tlic  other  sti'eaiiis,  and 
contains  mneh  less  o\i(K'  ot'  iron  and  less  of  tlie 
sulphates  than  the  pond  water.  It  gives,  l)y 
evaporation, — 

()i-g;iuie  nijitter,  in  grains  per  ^i^alloii,   1,120 

Inorganic  matter,      '*  "    2.091 

Solid  residue,     "  "    4.111 

In  the  inorganic  matter  I  detected  cldoride  of 
calcium,  the  presence  of  which  accounts  for  a 
remarkal)le  cloudiness  that  is  produced  as  the 
waters  of  the  l)rook  meet  those  of  the  pond.  For 
the  latter,  containing  soluhle  sulphate  of  iron  and 
alumina,  a  double  dec()mj)()sitioii  takes  place,  and  a 
cloudy  ])reci])itate  of  sul})hate  of  lime  is  produced, 
which  is  distinctly  perceptiMe  in  the  large  Lulk  of 
water,  though  not  noticeable  when  the  experiment 
of  mixing  is  tried  in  small  portions. 

Along  the  margin  of  the  2>oii<l  on  the  east  side, 

and  separated  from  it  by  a  sand-beadi,  are  ])ools  of 

water,  resulting  from  the  drainage  of  the  mnck  spoil 

l>anks;  these  are  the  gi'eat  collections  ot'  peat  and 

muck  that  \vere  extracted  from  the  bed      the  ])oii(l 

and  spread  o\-er  the  tields  in  its  \  icinity.     With  the 

vegetable  matters  there  occiirre(l  considerable  (|uan- 

tities  of  bisulplniret  of  iron,  and  more  or  le^^  clayey 
3 


14 


or  aluminous  earth.  As  tlie  heaps  lay  exposed  to 
the  Aveather,  the  iron  pyrites  decomposed ;  the  sul- 
phur, coml)ining  ^vith  atmospheric  oxygen,  formed 
sulphuric  acid,  and  the  iron  became  an  oxide,  with 
which  a  j^ortion  of  the  sulj)huric  acid  uniting  formed 
a  sulphate  of  oxide  of  iron  ;  ^vhile  another  portion, 
uniting  with  the  alumina  of  the  clay,  formed,  with 
the  former,  a  dou1)le  sulphate  of  alumina  and  iron. 
The  quantity  of  this  salt  was  sufficient,  Avhen  scat- 
tered over  the  surface  of  the  heaps,  to  be  every- 
where perceptiTde  during  the  warm  weather  in  the 
Summer,  in  the  form  of  an  efflorescence,  and  to  com- 
municate a  decided  sul])hurous  odor  to  the  atmos- 
phere around.  It  is  readily  dissolved  by  water,  and 
is  washed  down  by  the  rains  to  the  lowest  levels. 
The  ditches  along  the  margin  of  the  ])oiid  are  for 
the  purpose  of  catching  this  drainage,  and  prevent- 
ing its  entrance  into  the  pond.  This  is,  in  great 
part,  effected  by  the  sand  beach  ;  l)ut,  as  the  water 
in  the  pooh  rises  and  falls  ^y\^]l  that  of  the  pond, 
the  communication  between  them  is  not  entirely  cut 
off,  and  it  is  possible  that  some  of  the  impurities  of 
the  pools  may  filter  through.  The  examination  of 
this  water  aff()rds  an  indication  of  the  kinds  of 
impurities  that  may  thus  be  introduced ;  but  it  is 
to  be  remarked  that  the  quantity  is  likely  to  dimin- 
ish, as  the  superficial  layers  of  muck  becoine  ex- 


15 


liaiistcd  of  tlu'ir  saline  iiiatci  ials.  Indeed,  ]>y  coni- 
pai'ing  tlie  results  of  examinations  made  at  the 
interval  of  al)ont  four  months,  I  find  the  ])ro])ortion 
of  saline  matter  has  already  sensihly  diminished. 

The  water  of  the  ])ool  at  station  1'.)  is  remai'k- 
al)le  for  its  large  proportion  of  im])urilies.  It  is  of 
a  dee])  reddishd)ro\vn  eoloi-,  and  strong  styptic 
taste, — an  ounce  of  it  gives  distinct  crystals  of  the 
donl)le  salt  of  sulphate  of  oxide  of  iron  and  alumina. 
A  gallon  gives,  by  evaporation,  a  solid  residue  of 
183.059  grains,  consisting  of  inorganic  matter, 
T2 8.909  grains;  and  organic  matter,  with  watei*  of 
crystallization,  59.750  grains. 

The  water  from  station  21  is  highly  colored  hy 
organic  matter,  and,  in  September  last,  it  manifested 
even  to  the  taste  the  ])resence  of  a  considerable 
amount  of  the  double  salt  already  named.  In  De- 
cember, however,  this  had  nearly  disa])])eared.  A 
galhm  of  tlu^  ^^■ater  yielded,  l>y  evapoi'ati(>n,  a  solid 
residue  of  1*2. SlO  grains,  eonsisting  of  inoiganic 
matter,  T.<>74  grains,  and  oi'ganic  matter,  5.7(Uj 
grains. 

These  investigations  sngu'est  the  following  eon- 
clu<ions  : 

1st.  The  most  noxious  imj)urities  that  find  theii' 
way  into  the  water  of  the  pond  are  (h  iixcil  fiom 
sources  that  ai'e  rapidly  l»eeoming  exhausted  in  great 


10 


part.  And,  moreover,  tliey  undergo  such  clianges 
in  tlie  pond  that  tliey  are  converted  into  harmless, 
inert,  and  insoluble  compounds,  wliicli  are  likely  to 
remain,  to  considerable  extent,  as  precipitates  in  the 
pond  itself,  or  in  tlie  reservoir  at  Kidgewood  Hill, 
wliere  sediments  can  as^ain  subside  T)efore  the  final 
distribution  of  the  water. 

2d.  While  the  sup23ly  of  water  is  primarily-  de- 
rived from  the  purest  springs  of  the  diluvial  sands 
and  gravel,  the  contaminations  are  almost  wholly 
furnished  by  the  vegetable  deposits,  through  which 
the  streams  flow  before  they  are  discharged  into 
Jamaica  Pond.  Hence,  the  clearing  out  of  these 
channels  is  an  ol)ject  of  pi'imary  importance,  should 
any  objections  be  found  to  the  quality  of  tlie  water 
now  furnished  to  the  city.  Some  of  the  smaller 
streams  are  decidedly  sluggish,  and  their  course  is 
through  low  swamps,  of  similar  character  to  the  bed 
of  Jamaica  Pond  before  this  was  cleaned  out. 

The  experience  of  another  Summer  will  better 
determine  the  expediency  of  prosecuting  this  work, 
which,  the  further  up  the  sources  it  is  extended, 
must  unquestionably  increase  both  the  quantity  and 
the  purity  of  the  water  supplied  to  Brooklyn. 
Respectfully,  yours, 

A.  K.  EATON. 

72  Beaver  St.,  New  York, 
Jan.  nth,  1860. 


V  R  E  F  A  C  E 


It  will  he  iioticHMl  tliat  tlic  follow  ing  rcjxn't  was 
iviidcrcd  ill  ^Farcli,  ls(')(i,  l»ut,at  the  C()iiiinissi< )iici"s' 
suggestion,  a  t'lirtlier  iiKjiiiry  into  tlie  whole  amount 
of  fresh  ^\ater  discharu'ed  from  the  drainau'e-hasiu 
into  Jamaica  and  Hempstead  l>ays  \\  as  i-csolved 
ujMHi  ;  and  no  favorable  opportunity  offering,  while 
active  construction  of  the  Conduit  Extension  works 
was  progressing,  to  j)rosccute  the  necessary  (\\']H*i'i- 
nients,  a  eom])letion  of  the  re])oi't  w  ith  these  addi- 
tions ^\'as  conseipiently  postjxmed  until  the  Sum- 
mers AVork  was  finished.  It  ^vas  tliouuht  hcst  to 
incor])orate  the  result  of  the  investigations  in  rela- 
tion to  the  hay  into  the  hody  of  the  rc])ort,  rather 
than  append  it  in  a  sc])arate  form. 

Three  maps  anciv  tirst  made,  two  ol'  them  ex- 
hihiting  profiles  ot*  the  country,  on  rather  a  larger 
scale,  and  somewhat  more  in  detail  than  is  now- 
presented  ;  it  was  considered,  howcxt-r,  de-iral»le  to 
condense  the  \\hole  into  a  single  I'epre^eiitation,  as 
c>lfering  more  read\  lacilitie^  tor  comparison. 


18 


To  tliose  who  are  not  familiar  witli  tlie  character 
of  country  on  tlie  south  side  of  Long  Island,  or  with 
the  plan  of  water  supply  to  the  Brooklyn  Works,  it 
may  not  be  improj^er  to  briefly  explain  its  main 
features. 

From  Brooklyn,  where  the  contour  of  the  ground 
is  somewhat  broken,  the  irreofular  eminences  are 
collected  together  in  the  neighborhood  of  the  village 
of  East  New  York,  and  then  stretch,  as  a  single 
ridge,  very  directly  eastward,  dividing  the  Island 
into  two  portions, — that  on  the  north  l)eing  of  an 
aluminous,  heavy  soil,  of  which  the  ridge  itself  is 
mostly  composed ;  while  that  on  the  south  side  is 
entirely  sand,  of  a  very  equal  quality,  being  disin- 
tegrated granite,  probably  deposited  1)y  the  ocean 
currents  against  the  base  of  the  ridge,  which  seems 
to  have  been  the  terminal  morain  of  a  glacier.  This 
sand-deposit,  by  constant  accumulation,  has  grown 
out  into  the  ocean,  and  thus  the  plains  have  been 
formed  which  constitute  the  gathering  grounds  for 
our  AA'orks. 

The  drainage  of  the  country  between  the  city  of 
Brooklyn  and  Jamaica  has  not  in  any  way  been 
used  ;  l)ut,  from  the  neighborhood  of  that  village  to, 
and  rather  beyond  Hempstead,  the  water  yield  of 
the  country  has  l)een  appropriated.  The  drainage 
of  this  district  has  collected  itself  into  seven  con- 


19 


si(lt'ral>l('  st rc.-nii^,  wc   lia\('  <lr>iL:iiattMl  as 

Jamaica,  SpringHcld,  lirooklirM,  Clear  Slrcaiii,  \'al- 
ley  Stream,  Rockville  ami  llcmjjstca!!  ('recks.  Hie 
flow  of  one  ot*  tlicsc,  SpringHcld,  lias  not,  as  yct,lH'cii 
included  in  the  supply.  Each  of  these  streams, 
havini!'  a  fall  of  al>out  ei<>:ht  feet  ])ei'  mile,  and  Leinir 
from  three  to  eiuht  mik's  long,  lias  l>een  jxuided  at 
various  ])laces  since  the  settlement  of  the  Island, 
and  the  water  used  for  mill  |)urposes.  A  pond  on 
each  stream  ^^■as  purcliased  l>y  the  city  of  Brookh  n, 
and  the  right  of  taking  the  Avhole  floAV  gi'anted  that 
cor])oration.  These  ponds  ^vere  found  to  l>e  tilled, 
more  or  less,  Avith  decayed  vegetal )le  matter,  oi' 
muck,  de[)ending  in  amount  upon  the  length  of  time 
they  had  1)een  (hmnn(Ml  up.  Sections  of  them  are 
sho^\-n  on  the  ma]),  an  itli  the  depth  of  nuick  found 
in  each.  Xew  dams  were  carefully  consti'ucted,  with 
weirs  and  gatediouses  of  masonry.  From  each  a 
])arrel-conduit  of  brick,  varvinu'  from  '2  feet  to 
feet  ('»  inches  in  diameter,  takes  the  yield  ol'  the 
pond  and  emj)ties  it  into  a  lai'ge  acjueduct,  ANhich 
lies  ahout  one  third  of  a  mile  to  the  soutli,  and  the 
whole  collecte<l  tlow  i^  thence  carrie(l  lo  a  j>um])- 
wcll,  from  whicli  it  is  elevate<l,  l>y  two  steam  en- 
irines,  17<'  feet,  into  a  ic^ervoir  locate(l  on  the  ridL:«', 
about  five  mih'»  fiom  r)r<»oklyn  City  Hall,  and  from 
this  reservoir  thence  di-trihuted,   i»y   iron  ]»ij>es, 


20 


tliroiigliout  the  city.  The  bottom  of  the  main  aque- 
duct, where  it  begins  at  Hempstead  Pond,  is  about 
feet  above  average  high  tide,  and  descends,  as 
it  approaches  the  pump-well,  at  the  rate  of  (3  inches 
to  the  mile,  its  ^vhole  lens^th  beins;  a  little  more 
than  12^  miles.  The  water-surface  in  the  supply- 
ponds,  when  full,  is  from  8  to  15  feet  above  tide- 
Avater. 

The  material  composing  the  entire  district  being 
sand,  and  the  water,  therefore,  filtered,  is  very  pure 
and  cool.  By  the  arrangement  of  branch  aqueducts 
above  described,  each  pond  can  be  used  or  not,  as 
may  be  Avished,  or  the  "whole  at  once,  so  tliat  any 
one  of  them  may  be  repaired  or  cleaned  As  ithout 
interfering  with  the  delivery  of  the  others. 

It  is  hoj)ed  that  the  fe^v  facts  developed  in  the 
following  report  Avill  hereafter  l)e  confirmed  and 
more  thoroughl}'  illusti'ated  ])\  the  department  into 
whose  hands  the  charge  of  the  Avorks  Avill  ultimately 
fall.  A  thorough  familiarity  Avith  the  Avorking  of 
the  system  of  sui)ply  already  brought  into  service, 
and  a  full  understanding  both  of  the  necessities  and 
capabilities  of  the  supply-basin,  may  prove  of  much 
use,  not  only  to  the  city  particularly  benefitted,  but 
to  an  intelligent  development  of  the  Avater  resources 
of  other  districts. 

TlIEODOKE  WeSTOIS-. 

January^  1861. 


K  E  P  O  K  T 


Ja:\ik^^  p.  Kikkwooi),  Esq., 

K)ujlnccr  Ih'ooIJ ijn  Wcdo'  Worlx. 

^Iy  Dkaii  Siii  : — Wlicn,  in  XovemluT  last,  you 
desired  iiie  to  ascertain  tlie  ae'Cfreo-ate  drainao-e  area 
of  the  great  hasin  whence  the  su])})ly  to  onr  works 
is  derived,  I  did  not  at  once  perceive  wliat  interest- 
ing (picstions  w(M'e  C()ni])r(^liend('d  in  tliis  examina- 
tion, nor  how  far  faitliful  and  continuous  inves- 
tig^ation  was  necessarv  to  determine  witli  accuracv 
the  extent  and  jx'cullarity  of  tliis  su])])ly;  and, 
thougli  yoiii'  restrictions  did  not  admit  of  my  under- 
taking a  cai'ei'ul  toj)ograi)hical  and  liydr<»metric  sur- 
vey of  tlie  district,  I  am  convinced  tliat,  in  j)rosecut- 
ing  my  in(|uiries  somewliat  further  than  you,  per- 
lia])s,  intelKhMl,  y<.u  w  ill  not  onl\-  see  that  the  su1>ject 
chiime(|  this  additional  att<'ntion  on  our  part,  l)ut 
will  I'ecognize  the  importance  ot'  collectiiiL^-  niucli 
more  careful  and  elalxn-ate  data,  from  which  to 
deduce  any  just  and  relial»le  results. 
4 


00 


The  constant  attention  wWcli  the  construction  of 
the  Conduit  Extension  required  from  the  available 
engineering  force  in  the  Company's  service,  prevent- 
ed my  taking  up  the  drainage  survey  with  any 
vigor  until  the  5th  December  last,  when,  joining  the 
parties  at  my  disposal,  I  was  enabled,  by  uninter- 
i*u]jted  and  rapid  surveillance,  to  complete  most  of 
the  necessary  field  operations  by  the  1st  January. 

The  interval  which  has  since  occurred  has  been 
consumed  in  preparing  the  accompanying  draAvings, 
and  collecting  such  information  as  I  judged  would 
prove  useful  in  explaining  the  character  and  capacity 
of  our  storage  T)asin.  If  this  interval  has  seemed  to 
you  unnecessarily  prolonged,  I  trust  the  claims  of 
other  portions  of  the  work  upon  our  time  will  suffi- 
ciently excuse  any  apparent  delay  in  submitting  the 
results  of  our  labors. 

It  was  made  tlie  especial  ol)ject  of  the  survey, — 

1st.  To  ascei'tain  the  actual  peri])hery  of  the 
entire  drainage  district. 

2d.  To  discover,  as  nearly  as  possil)le,  the  drain- 
age limits  of  the  different  streams  ;  and 

8d.  To  determine  the  depth  of  the  subterranean 
spring  level  below  the  surface. 

As  the  readiest  method  of  effecting  these  pur- 
poses in  the  rapid  manner  proposed,  it  was  decided 


23 


to  follow  uj)  the  iiiiiiici-ous  roads  wliicli  cut  the 
country  in  every  (lireetioii,  ascertaining  their  eoiiloiir 
and  neigldmring  topogra])liy,  and  invariably  deter- 
mining the  water  levels  in  all  contiguous  wells. 
Important  vallcNs  and  streams  which  c()uhl  not  l»e 
thus  reached  were  separately  sur\e\('d,  and  sulli- 
ciently  far  to  learn  their  extent  and  direction. 

The  ag^ofrcecate  leiis^tli  of  line  so  run  amounted  to 
miles  (tlie  ])osition  and  distribution  of  ^\llicll 
is  sliown  (HI  tlie  accompany  ing  map). 

The  fre(pient  intersection  of  these  roads  gave 
al)un(hint  o])portunity  of  correcting  and  verifying 
all  instrumental  work,  tliougli  no  error  of  any  im- 
portance was  detected. 

Some  25  mik^s  of  former  surveys,  by  engineers 
previously  em])loyed  on  ])lans  for  the  AVater  Works, 
and  a  portion  of  the  j)i*ofile  of  the  Long  Island  Kail- 
way  (l)etween  Hempstead  and  Jamaica),  obtained 
fr(nn  the  office  of  the  President  of  that  C'om]»any, 
were  ap})roj)i'iated  and  used  in  the  construction  of 
the  maj>  I'eferrecl  to  in  this  report. 

^'ou  will  ])crcei\('  that  this  ma])  is  intende*!  to 
exhibit  the  extent  and  tbrm  of  the  se])arate  basins, 
and  to  indicate,  also,  the  length  and  beai'ing  of  the 
m<»re  imj)ortant  vabeys  and  streams,  both  tlio^e  con- 
tributing to  our  su]>j)ly,  and  th<)se  una\ailal>h'  to 
US.     Tlie  cont<>ur  of  the  spring-water  surface  is 


24 


designated  by  the  Ijliie  lines,  wliioli  are  traced  on 
the  map  at  intervals  of  10  feet,  between  elevations 
of  15  and  50  feet  above  mean  hisfh  tide- water. 

Profiles  of  the  ground  smfacef  and  water  bed 
at  various  points  are  also  given,  the  portion  of  each 
which  is  colored  blue  indicating:  the  heicrht  at  which 
the  spring  water  is  found  above  datum  base.  The 
vertical  lines  on  the  profiles  are  the  Avells  whose 
surfiices  were  ascertained  by  direct  and  careful  meas- 
ui*ement.  Sections  across  the  various  supj^jly  ponds 
are  added,  in  order  to  show  the  relative  amount  of 
muck  deposit  Avhicli  had  accmnulated  in  each. 

In  looking  over  the  map,  your  familiarity  with 
the  region  there  represented  renders  it  hardly  neces- 
sary for  me  to  describe  its  ordinary  features ;  it, 
liOAvever,  may  not  he  altogether  improper  to  call 
your  attention  to  some  of  its  more  prominent  pecu- 
liarities in  connection  Avith  the  facts  which  have 
been  elicited  by  our  sui'vey. 

The  northern  limit  of  tliis  basin  is  the  well- 
defined  chain  of  hills,  Avliich  is  a  part  of  the  great 
dividing  line  of  Long  Island ;  its  southern  boundary 
is  the  line  of  arpieduct,  now  in  process  of  construc- 


*  Wherever  levels  are  mentioned  in  this  report,  they  are  invariably  to 
be  referred  to  this  datum-base  used  in  the  construction  of  our  works. 

f  Elevations  of  the  ground  surface  were  taken  at  stations  200  feet  apart. 


25 


tioii  ^\■lliU'  its  eastern  and  wcstci'ii  extremities  are 
teriiiiiiated  hy  lines  nearl}  at  liglit  angles  to  the 
ridge.  The  annual  preei])itati(>n  of  rain  and  snow 
upon  the  surfaee  ineludcMl  in  these  limits  is  the  sole 
souree  of  its  ^vater  supply. 

This  district,  }'ou  w  ill  see,  readil\  divides  itself 
into  two  distinct  portions  : — 

1st.  The  ridge  and  its  slopes  constituting  a1»out 
one  t^velfth  the  drainage  area,  having  a  compact  and 
conglomerate  soil,  generally  im])ermeal)le  to  Avater  ; 
and 

2d.  The  table  land  lying  at  its  l)ase  comprising 
the  remainder,  and  liaving  a  soil  of  very  porous  and 
ahsorl )ent  character. 

The  crest  of  the  ridu'e  i^  exceedinu'lv  irreu'ular, 
and  marked  hy  de})ressi()ns,  Avhose  suljstratum  is 
often  a  bed  of  ela}',  which,  collecting  tlie  surface 
Avater  of  many  acres,  holds  it  in  the  form  of  mai'she^ 
or  small  ])onds,  and  allows  it  to  esca])e  only  l>y  sl<>\v 
tilti'ation  and  eva])oration.  The  southern  slojx*  of 
the  ridge  is  more  uniform,  and,  turning  off  most  of 
the  rain-fall  uj)on  the  sand  plain  helow,  may  he 
pr(»])erly  considei"e(l  a  ])art  of  our  gathering  ground. 

.\s  the  shore  line  of  the  l>ay  and  this  ridge  con- 

*  The  ritic  of  Coiuluit  ExU-n.sion  lies  so  Tu-arly  at  ihv  natural  I'd^^e  of  tlu- 
basin,  that  1  have  considered  it  nio^t  convenient  to  assume  it  as  our  south- 
ern boundary. 


26 


verge  toward  tlie  western  extremity  of  the  basin,  we 
find  the  elevations  of  both  plain  and  ridge  propor- 
tionately diminishing  toward  that  end,  at  an  average 
rate  of  12  feet  per  mile  for  the  former,  and  17^  feet 
per  mile  for  the  latter."^'  The  face  of  the  hill  slope, 
as  yon  will  remember,  is  very  steep,  having  a  mean 
inclination  of  al)out  one  foot  in  six  ;  from  its  base 
the  table  land  thence  falls  towards  the  bay,  at  a 
varying  rate  of  from  12  to  27  feet  per  mile. 

The  contour  of  this  taljle  is  mostly  even,  and 
especially  the  eastern  portion,  AN'hich  includes  the 
Hempstead  Plains ;  it  becomes,  hoAvever,  more  un- 
duhiting  as  the  Jamaica  end  is  approached.  We 
find  a  large  proportion  of  it  under  cultivation,  or 
open, — the  forests,  marshes,  etc.,  not  exceeding, 
probably,  one  -seventh  the  entire  area.  After  strik- 
ing through  the  surface  soil  of  shallow  loam,  a  sub- 
soil of  clear,  clean  sand  is  universally  found,  an  hose 
constant  character  is  undoubtedly  preserved  to  a 
great  depth  beneath  ;  and  it  is  this  great  sand  bed, 
the  interstices  between  whose  particles,  up  to  a 
certain  level,  are  filled  with  water,  which  constitutes 
the  storage  reservoir  whence  our  supi:>ly  is  drawn. 

*  AVhile  the  ridge  is  some  niiles  from  tide-water  at  the  east  end  of 
the  basin,  it  is  but  21,000  feet,  or  4  miles,  at  the  Jamaica  end. 

An  elevation  of  366  feet  was  reached  upon  the  highest  knoll  of  the 
Harbor  hills,  and  one  about  195  feet  high  north  of  Jamaica, 


27 


Tlio  subterranean  surfaee  tliis  reservoir  eoii- 
toriiis,  ill  oviieral,  to  tlie  slope  of  tlic  ])laiii  ;  Imt,  as 
you  would  expect,  it  lias  inueli  riioic  reirularity,  and 
it  is  only  at  the  southern  extremity  of  tlu'  l»asiii, 
where  it  lies  very  near  the  to])  of  the  ui'ound,  that 
any  undulations  are  eons])ieuous.  Occasional  d(^- 
])artures  or  variations  from  this  oc'iu-ral  fact  may, 
however,  he  ex])lained  hy  the  prol)a])le  existence  of 
soiiK^  impeneti'ahle  or  disturl)ing  stratum  under- 
neath ;  such,  for  instance,  as  you  Avill  ohscrve  in  tlu^ 
Hyde  Park  protile  at  Herrick's  Pond,  and  hetween 
Springfiehl  and  Prookficld  in  the  Jericho  turn])ike  ; 
and,  in(hn^d,  ^ve  are  ^\  ell  ^\  arranted  in  ascrihing 
them  to  this  cause,  since  the  excavations  upon  our 
works  have  revealed  cases  of  similai*  ireoh^irieal 
peculiai'ity  and  ^\  e  may  presume  that  the  regular 
le\-el  of  storage  would  still  he  found  l)elo^\■,  at  its 
proper  elevation. 

The  uiiifoi'iiiity  of  the  water  slojx'  will  he  seen 
on  comparing  the  grades  of  the  separate  ])rofiles; 
thus,  tlie  rate 

F(.r  Ih'ookfield  road  is  -2.4  feet  ])(*!•  1,000  feet. 
Springfield  2A\  " 

Valley  Stream"       2r2   "  " 

"    Kockville       ^'       i>.4  " 


*  The  bhu'-clay  lietl  fouiul  ten  foet  uiuler  the  saiul.  at  !>tatioii  oTO  of  Con- 
duit Kxtension  line-.     a  noticeable  instance  of  this 


28 


Indicating  an  extreme  difference  of  but  two  feet  per 
mile, — a  condition  so  invariable  that  we  may  reason 
upon  it  witli  great  certainty,  while  it  affords  the 
strongest  testimony  to  the  permanent  character  of 
the  supply. 

Having  now  recalled  to  you  these  more  prom- 
inent features  belono^ino;  to  the  reoion  under  con- 
sideration,  I  shall  first  direct  3  our  attention  to  the 
computed  extent  of  various  suT)divisions  of  the  dis- 
trict, and  afterwards  submit  to  you  a  few  calcula- 
tions, based  upon  what  little  information  I  have 
been  able  to  collect,  which  may  possibly  assist  in 
giving  you  some  idea  of  the  great  capacity  and  con- 
stancy of  our  storage  reservoir. 

The  drainage  ground  comprises  a  total  area  of 
73.64  square  miles,  liaving  an  average  length  of 
about  12  miles,  and  a  mean  widtli  of  little  more 
than  6.   It  may  be  subdivided  into  six  poi'tions  : — 

1st,  Jamaica  Creek  and  its  tributaries,  10.88  sq.  miles. 

2cl,  Brookfield  and  Clear  Stream  Creeks,. .  .  8.87  " 
od,  Valley  Stream,  or  East  Tlook  Creek 

Branch,   0.38  " 

4th,  Rockville  Stream,   8.31 

5th,  Hempstead  Creek,  25.79  " 

00.23  " 

Gth,  Unappropriated  streams,*  13.41  " 

73.G4  " 

*  The  uncertain  yield  wliich  is  likely  to  be  derived  from  the  taps  pro- 
posed in  the  sides  of  the  aqueduct,  and  the  difficulty  of  ascertaining  the 


29 


Tli(Miii;i])])r<)])riat(Ml  portion,  (listiiigiiislitHl  l)ytli(* 
])iiik  lint  ill  tlu*  ma]),  may  Ix'  t'lii'tlier  sulxlix  idcd, 
as  follows  : — 

3.44  sq.  miles, — Tiie  region  included  hclwecn  Conduit  Ex- 
tension and  a  line  eonneeting  the  dams 
of  supply  ponds. 

5. GO  Di-ainage  of  Springfield  Valley. 

1.72  "  Valley  Stream. 

2.05  Foster's  Brook  and  adjoining 

streams. 

i:i.41 

It  will  he  seen  that  00.2 square  miles,  or  82  per 
cent,  of  the  whole  district,  contrihutes  to  the  supply 
ponds,  \vliile  the  remainder  passes  its  waters  off 
under  our  conduit,  })y  the  culverts  provided,  and 
they  are  thence  carried  to  the  sea. 

Althoiiuh  the  aggregate  area,  as  stated,  is  ])rol)- 
a])ly  very  near  the  truth,  the  sul)divisions,  as  shown 
in  the  ma]),  must  ht^  regarded  as  more  uncertain. 

Were  ours  a  mere  surface  drainage,  the  ridges 
hetween  the  sti'eams  would  indicate  ti'idy  the  ])roper 
water-sheds;  hut  since  tliey  are  led  mostly  from 
springs  cro])])iiig  out  at  \arious  ])oiiits  in  tlieir 
coni'se,  all  coming  from  the  great  1('\ cl  water-lxMl, 
whose  regnlar  siirt'ace   was   remarked   ahove,  tlu* 

distance  bjick  from  these  deliveries  at  whieli  the  water  bed  would  be  affected, 
has  led  me  to  reject  altoj^ether  the  re<i;ion  drained  by  tlimi  as  a  ]>ai  t  of  our 
gathering  ground  ;  it  must,  however,  be  quite  small. 


80 


distance  from  the  edge  of  the  stream,  where  the 
influence  of  each  ceases,  is  very  difficult  to  conjec- 
ture. 

Toward  tlie  mouths  of  tlie  creeks,  wliere  the 
undulation  of  ^vater  follows  the  roll  of  the 
ground,  we  may  determine  the  separations  quite 
distinctly ;  l)ut,  as  we  approach  their  sources,  where 
no  such  correspondence  occurs,  we  must  evidently 
locate  them  with  great  uncertainty  ;  it  is  prohable^ 
indeed,  that  they  merge  into  each  other,  very  slight 
causes  controllino^  the  direction  of  the  discharo^e. 
Between  the  base  of  the  rido^e  and  the  heading'  of 
the  streams,  a  large  space  intervenes,  through  which 
the  water  is  very  equally  distributed,  and  which,  in 
fact,  can  pro])erly  have  no  subterranean  water-ridge. 

The  rate  of  fall  of  the  stream  does  not  commonly 
coincide  witli  the  i*ate  of  the  underground  water- 
slope, — the  foi'mer  1)eing  ordinaril}'  al)out  10  feet 
per  mile,  while  the  latter,  it  was  discovered  above, 
preserves  a  uniform  grade  of  1 2  :| .  Vs^e^  consequently, 
find  the  surface  of  the  stream,  as  it  approaches  the 
southern  edge  of  the  basin,  flowing  al)ove  the  stor- 
age surface  ;  if,  therefore,  an  adjoining  l)rook  is  in  a 
loAver  valley,  it  nmst  apparently  draw  beyond  the 
middle  of  the  distance  between  the  two.  Brookfield 
Stream,  for  instance,  is  ponded  at  an  elevation  of 
15.4  feet,  while  Clear  Stream,  adjacent,  is  but  10  ft. ; 


81 


and  ^^'('  should,  course,  iiit'cr  that  tlic  latter  would 
yield  a  larger  j)ereentage  of  watei',  in  proportion  to 
its  leugtli  and  iiuj)()rtaneo,  tlian  the  tonner ;  and,  in 
.some  degree,  it  pi'ol)al)ly  does,  tliougli  it  is  luueli 
less  than  Avould  l>e  su})[)osed,  and  not  enough  to 
materially  afKeet  the  location  of  tlie  di\  ide. 

AVitli  reference,  tlien,  to  sucli  conditions  of  dis- 
charge as  our  limited  observations  suggested,  1  liave 
attempted  to  trace  tliese  water-ridges,  indicating  tin* 
surface-ridges,  l)y  lines  of  shading,  and  making  tliem 
commonly  tlie  guide  for  the  direction  of  tlie  reser- 
voir outline  underneath. 

If,  now,  \\  ('  adopt  these  subdivisions,  as  estimated 
in  the  above  areas,  and  compare  each  Avitli  the  mini- 
mum floAv  of  the  drainage  stream  belonging  to  it,  as 
given  in  your  re[)ort  of  January,  1858,  the  following 
tal)le  is  o])taine(l : — 


1 

Am't  (low  per 

No.  gal.'s.  per 

No.  pals. 

Districts. 

Area  drained, 

day,  ' 

day  per  sq. 

per  day 

s(i.  niilfs. 

N.  Y.  gals.  ' 

mile. 

per  acre. 

.Taiiiiiita  

10.88 

;^.()r);>.7i)2 

280,677 

439 

Brookficld  ami  Cl.  St. .  . 

8.87 

2.<U7,r)3()  \ 

295,1(10 

461 

(•>.:',  8 

2.;588.:i(»r)  ! 

371,342 

585 

liockville  

8.:U 

2.569.320  ' 

309,184 

18;] 

2.-).  79 

7,651,321 

296,677 

463 

Total  and  mean  

(ift.'J!:-! 

18.280.530  1 

303,515 

47t 

i:;.  11 

1,00:3,230 

303,515 

474 

;  73.64 

22,343,760 

The  unappropriated  portion  in  the  table,  you 
will  notice,  is  calculated  to  yield  4,063,230  gallons, 
— a  quantity  answering  to  the  mean  drainage  per 
square  mile  of  the  other  five  districts. 

It  is  seen,  from  the  above  schedule,  that  Valley 
Stream  gives  the  highest  I'ate  per  square  mile,  and 
Jamaica  the  lowest;  while  the  others  differ  very 
little  from  each  other.  In  the  case  of  Valley  Stream, 
it  is  not  inq)robal)le  that  too  little  area  is  assigned 
its  drainage  territory ;  still,  the  flow  of  the  stream 
is  very  direct  and  single,  its  only  tributary  uniting 
with  it  below  our  dam,  and  largely  augmenting  its 
volume.  The  circumstances  of  a  free  dischars^e  of 
the  bordering  springs  into  its  channel  is  very  favor- 
able, the  ridge  on  either  side  l)eing  high,  and  the 
dip  of  the  Avater-bed  strong  toward  the  stream. 

In  comparing,  hoAvever,  tlie  form  and  features  of 
the  Jamaica  district  A\'ith  the  remainder  of  the  T)asin, 
the  mrface  character  of  its  drainage  is  very  appar- 
ent. Small  brooks  or  arms  shoot  off  in  every  direc- 
tion, and  the  springs  discharge  feebly,  the  mean 
storage-head  being  but  12.9  feet  above  the  plane  of 
the  full  pond  into  Avhich  the  Avhole  water  is  deliv- 
ered. Beaver  Creek,  which  rises  near  the  T)ase  of 
the  main  ridge,  and  is  more  immediately  supplied 
by  lateral  springs,  is  its  coolest,  clearest,  and  most 
constant   tril)utary,  but  yet  does  not  contribute 


eiiouo'll  to  o'ive  characU'r  to  (lie  pond,  wliosc  Avatci' 
is  noticeal)ly  difl'ereiit  i'low)  I  he  otlu  rs  lo  tlic 
east.  Our  experience  in  its  management  also  indi- 
cates that  it  is  more  readily  and  to  a  greater  extent, 
affected  l)y  Hoods. 

Of  tlie  remaining  sub-districts,  notliing  in  tlieir 
physical  conditions  recpiires  especial  remark;  tlie 
flo\v  of  tlieir  various  drainage  streams  is  (piite 
similar  and  unitbi'm,  both  in  volume  and  (piality. 

Considering  the  resulting  mean  deri\'ed  from 
the  tal)le  as  approximating  the  trutli,  Ave  liave  a 
toleraldy  relialde  calcuLating  unit  for  the  natural 
yield  })er  s(|uare  mile.  If  Ave  assume,  therefore, 
datum  high  tide  i)lane  as  the  bottom  of  our  whole 
storage  district,  and  neglect  all  al)sorl)ing  capacity 
beloAV  that  plane,  by  tirst  determining  the  average 
heisfht  of  saturation  throusrhout  the  basin,  and  the 
amount  of  watei*  ^^  hich  each  cubie  f>ot  of  sand  \\  \\\ 
hold  in  its  interstices,  we  may  readily  com[)ute  the 
whole  (juantity  stoi*ed  in  the  district. 

1^'roni  (»ur  niaj),  the  water  surface  is  aseertained 
to  ha\('  a  mean  level  of  '>1  feet  above  the  ]»lane 
assume(l  :  and,  from  the  results  of  several  e.xpeii- 
nients  directed  to  this  end  (details  of  which  ai-e 
gi\-en  in  Table  A,  at  the  end  ),(>..')( )  i>  lixed  .-i^  the 
storage  sj)ace  in  each  cubic  foot  (»f  (»rdinary  material 
composing  the  sand-l)ed.     The  area  of  the  l»asin, 


34 


then,  being  73.64  square  miles,  or  2,052,670,816 
square  feet,  by  applying  the  units  above  our  calcu- 
lation gives  us  19,459,319,335  cubic  feet  water  in 
store, — a  quantity  sufficient  to  yield  20,000,000  gal- 
lons per  (lay  for  nearly  nineteen  years,  apart  from 
the  yearly  addition  by  ordinary  precipitation  to  its 
reserve.  The  same  reasoning  may  manifestly  be 
followed  in  estimating  the  reserve  of  each  sub-area, 
new  depths  being  found  for  every  separate  district. 

The  subjoined  table,  in  Avliich  I  have  computed 
the  depths  above  the  plane  of  each  pond  surface 
Avhen  full,  will  give  you  their  relative  storage  capac- 
ities above  those  levels  : — 


■  storage 
pond. 

DISTRICT. 

Level  of 
full  pond 

Surface  of 
above  full 

Area 
of  district. 

Min. 
daily 
flow. 

Amount 
held  in  store. 

No. 
days 
reserve. 

Ft. 

Ft. 

Sq.  feet. 

Cub.  feet. 

Cub.  feet. 

Jamaica,  

Brook  field,  ) 

Clear  Stri-aiii, .  .  .  f 

Valley  Stream, .... 

,  PvockVille,  

1  Hempstead,   

l| 

8.0 
15.4 
10.0 
12.8 
13.0 
10.6 

12.9 

20.3 
34.4 
38.4 

299,570,000 
IVY.T^o.ooo 

231,C.'j:),«'i>() 
7l9,26o,0»)(» 

391,010 

30.-,, 801 
979,683 

1,162,032,030 

1,083,564,000 
•J,:;93,844,375 
6,866,754,472 



2,792 

3,543 
7,276 
7,009 

So  large  a  I'eserve  fis  is  here  indicated  for  each, 
must  prevent  the  flow  of  any  of  the  streams  from 
becoming  seriously  diminished  by  drought ;  nor, 
probably,  would  the  stored  amounts  vary  much  from 


35 


year  to  yeai",  llie  extra  i)i'('('ij)itat ioii  ])as>;iim-  oil'  l)y 
increased  discliai'Li'e  t liroiiLili  the  sti'caiiis. 

We  may  now,  1>\  takinu"  tlie  mean  rain  Tall  njjon 
the  general  district,  jnduc  still  tnrt  her  < )t*  it s  caj)acity 
and  constancy,  and  discoNcr  liow  nincli  may  he 
dra\vn  away  witliont  injni'v  to  this  reserve. 

Estimating  tlie  avei'age  j)recij)itation  at  42yy- 
inclies  ])cr  year  on  each  sijuai'e  toot  ot*  area,"'  \ve  tind 
that  it  wouhl  liave  required  iij) wards  of  tliree  years 
to  liave  tilled  the  Lasin  witliont  any  w  aste  occurring, 
either  troni  eva])oratlon,  vegetaLle  al)soi'j)tion,  oi' 
hy  discliarge  througli  the  springs  and  water  coui'ses ; 
and  that,  allowing  tor  these  natural  h)sses,  it  would 
have  taken  not  less  than  twelve  veai's  to  l)rinL''  the 
reserve  up  to  its  present  level. 

We  see,  C()nse(piently,  that  the  small  \  ai'iations 
of  a  season's,  oi*  even  a  year's,  rain-fall  can  affect  the 
resei've  height  hut  slightly,  compelling  us  to  I'ecog- 
nize  AN'ithout  hesitation  the  certainty  an<l  ])erma- 
ncncN'  of  onr  snj)])ly.  f' 

Being  convinced,  then,  of  its  great  ca])acity,  it 

*  This  moan  is  made  up  tVom  the  three  tables  (W,  C,  and  D)  apijended. 
The  Jamaica  record,  you  will  j)ereeive,  is  tlu-own  out  a<  entirely  unre- 
lial.le. 

f  The  <;-eneral  ti-iith  here  stated,  respeetiiis;  the  constancy  of  the  water- 
surface  in  tlie  moan  area  of  the  basin,  admits,  however,  of  some  ijualitieation 
when  applied  to  it><  -southern  or  dis(  haruiui;-  edoc.  As  befi.ir»'  remarked,  the 
level  of  this  rei'/ion  of  the  ri-serve  lies  \ cry  near  the  -urfaci.'  of  the  Lrrountl. 


86 


becomes  interesting  to  know  wliat  proportion  of  tlie 
annual  rain-fall  is  passed  off  tlirougli  our  supply- 
streams,  and  made  availal)le  to  us  hy  tlie  present 
location  of  tlie  works.  And  tliougli  we  liave  made 
no  experiments  sufficiently  definite  to  determine  tlie 
evaporation,  or  vegetaT)le  absorption  in  our  own 
district,  Ave  still  have  enougli  data  to  compute  the 
total  percentage  of  loss,  and  thence  judge,  from  the 

and  the  rain-fall,  readily  penetrating  to  it,  produces  fluctuations  in  its  height, 
corresponding,  in  some  degree,  to  the  variations  of  precipitation. 

The  following  table  of  comparative  elevation  of  several  pits  and  wells 
near  the  line  of  our  works,  taken  at  different  periods,  to  which  I  have  at- 
tached a  profile  of  rain-fall  for  corresponding  periods,  will  illustrate  this  fact 
to  some  extent : — 


Elevations  above  tide-base. 

■| 
1 

! 

Extreme 

1 

WELLS. 

u  x 
c '-' 

3 

o 

fluctuations. 

"-J 

o 

S5 

Feet. 

Feet. 

Feet. 

Feet. 

Feet. 

Feet. 

Xo.  1, 

2.94 

1.52 

2.35 

3.03 

1.51 

Earth,  covering  from  2  to 

{ 

"  2 

3.64 

2.63 

3.38 

1.01 

5  feet  deep,  

"  si 

7.70 

4.81 

6.18 

7.31 

2.89 

1 

"  4, 

6.72 

5.40 

5.97 

1,32  i 

"  5, 

6.08 

5.96 

5.91 

0.17  1 

Earth-covering  from  8  to 

1 

"  6, 

1.35 

1.36 

1.70 

0.35  i 

1 2  feet  deep,  

"  7, 

5.66 

5.72 

6.03 

0.37 

"  8, 

7.17 

7.44 

7.31 

0.27 

A  comparison  of  the  table  and  profile  would  indicate  that,  though  the 
rain-fall  of  the  Summer  months  considerably  exceeded  that  of  the  Autumn, 
yet  the  surface  of  the  water  bed  sunk  until  cool,  unevaporating  weather  set 


37 


common  experience  in  otlier  regions,  ^vllat  ])r(>])oi"ti(>n 
properly  Leloni^s  to  these  two. 

In  }  onr  I'eport  of  1858,  }'()n  collected  some  iiitor- 
mation  relating  to  surtace-evaponition,  to  Avhieli  I 
have  l)een  nnal)le  to  add  anything  more  reliahh'  or 
extended,  ])e}'ond  the  mere  general  inferences  an  hich 


Prohi.k  of  JLun  fai.i.  from  Mav  to  XovKMnKR,  18r)7  (incu  sivk). 

in;  mill  \vc  iiiu>t  presiiiuc,  tlicn-forc,  thai  iicai-ly  all  llic  pn-cipitatioii  of  tlio 
liot  inonlhs  was  tlissipated  before  it  reached  the  under-j^round  reserve. 

You  will  observe,  also,  that  the  deeper  wells (tlujse  liii^licst  above  datum) 
were  i^rnerally  more  eoiistaiit, — the  extreme  ibu  tuation  of  Nos.  T).  0,  7,  and 
8  beini;  small  beside  Xus.  1,  2,  ;i.  ami  1,  which  ha\i'  much  less  earth 
covering. 

() 


38 


are  inapplicable  to  special  districts  like  our  o^yn. 
Mr.  Stirrat,  however,  whom  I  think  you  quote,  in 
evidence  before  the  Parliamentary  Committee  of 
1850,  states  that,  Avhile  Mr.  Thom  had  previously 
reckoned  on  a  loss  of  66  per  cent,  of  the  annual 
rain-fall  in  the  Paisley  district,  subsequent  experi- 
ence had  proved  that  it  was  but  33  in  those  gather- 
ing gi'ounds, — an  amount  much  below  the  common 
estimate.  Mr.  Donaldson,  before  the  same  commit- 
tee, affirms  that,  at  Eichnioiid  Park,  but  10  out  of 
25  inches  fall  ^vas  available  ;  in  other  Avords,  that 
60  per  cent.  Avas  lost.  Both  these  districts  ^vere 
largely  drained  by  the  subsoil  system. 

Mr.  Ellet,  in  a  report  rendered  Se})t.  11th,  1819, 
and  puljlished  among  the  Smithsonian  contributions, 
as  the  result  of  careful  observation  throughout  the 
feeding  district  of  the  u])per  Ohio,  states  the  mean 
loss  to  be  60  per  cent. ;  and  I  think  it  Avill  ])e  found 
that  the  most  intelli2:ent  estimates  rather  exceed 
than  tall  l>elow  this  figure.  We  nuist  expect,  con- 
sequently, in  our  sand  countr}',  to  calculate  for  at 
least  an  ecjual  amount,  and,  as  the  following  compu- 
tations Avould  suggest,  possibly  still  more. 

If  the  average  flow  of  any  one  of  our  streams  he 
deducted  from  the  mean  annual  rain-fall  upon  the 
districts  named  by  it,  Ave  have  at  once  the  comj^ara- 
tive  available  percentage.    I  have  fixed  the  average 


39 


flow,  in  the  ahsenee  of  any  oontinuons  record,  at 
two  tliirds  more  tlian  the  niininiiiin  s(4  (h>wn  in 
}'our  re])ort  a1)ove  reteii'e(l  to;  and  tliougli  ^'ou 
wonhl  ])resiinie  tliis  to  ])e  large,  you  ])ereeive, 
from  tlie  tahle  helow,  that  tlie  actual  k)ss  in  tlie 
district  is  so  o-reat  that  consi(h*ral)le  differences  in 
the  daily  discharge  of  the  streams  would  not 
especially  atfei-t  the  average  results : 


i 

DISTRICTS. 

Area 
drained. 

Total  yearly 
rain. 

Min. 
flow 
per  day. 

Ave. 
flow 
per  day. 

Total 
yearly 
"flow. 



Per  centum 
of  loss. 

Jamaica,  

Brookf'd  &  Ci.  St. 
Valley  Stream,. .  . 

Rockville,  

Hempstead,  

Sq.  feet. 

299,570,000 
240,155,000 
177,750,000 
281,625,0(X» 
719,205,000 

Cub.  feet. 

1,000,477,800 
871,3^8,700 
629,235,000 
819,952,500 

2,^6,198,100 

Cub.  ft. 

391,010 
835,280 
805,801 
32S,97> 
979,683 

Cub.  ft.  1   Cub.  ft. 
C52,(HMI  23^,(ls(),0(M) 
5.">S,800  208,962,(K)0 
510,10(1  lS(i,ir)(t,004) 
548,500  2(M».202,5<H) 

l,6;32,650j  595,91 7,250 

77  S-10 
76  6-10 
70  4-10 
75  6-10 
T6  (>-10 

;  Total  and  mean, . .  j 

5,927,252,100  2,;340,752  3,902,05«  | 

1             1  1 

75  4-10 

These  ])ercentages  ai'e  the  losses  in  each  ])articu- 
lar  sul)-disti'ict  ;  l)ut,  to  reach  the  ti'ue  mean  for  the 
wliole  Lasin,  we  must  add  to  that  given  in  the  talde 
the  amount  due  u])()n  the  una})})r()priated  area,  wliicli 
is  found  to  l>e  l,82r),9r)0,()()0  cubic  feet, — increasing, 
conse(iuently,  the  total  mean  to  7S  ]^er  cent. 

A  \'ery  considerable  ])ro})ortion  of  this  must  he 
credited  to  the  ^vaste  from  springs  erop])ingout  Ixdow 
the  line  of  our  su})ply  reservoii's,  ]>ut  which  are  fed 
from  the  same  storage.  \\\  gaugings  made  on  two 
streams  (^Watts  and  lirooktleld ),  detailed  reports  of 


40 


wliicli  I  returned  to  you  in  August  last,  and  wliicli 
you  will  find  in  tlie  Appendix  (marked  E  and  F), 
the  increased  volume  for  eacli,  at  somewhat  less  tlian 
a  mile  l)elow  tlie  city's  present  ownersliiji,  was  dis- 
covered to  be  yV  more  at  a  time  of  minimum  flow. 
This  ratio  would  undoubtedly  l)e  reduced  during  a 
period  of  maximum  or  average  discharge,  when  no 
additional  want  could  be  felt,  and  need  not,  there- 
fore, be  considered.  At  the  a1)ove  rate,  then,  15  per 
cent,  of  the  precipitation  would  T)e  due  to  this  sub- 
terranean loss, — leaving,  therefore,  08  per  cent,  to  ])e 
divided  between  the  necessities  of  vegetal)le  life  and 
the  waste  of  evaporation. 

The  aA^erage  daily  flow,  it  is  seen  from  the  state- 
ment in  the  table  just  given,  yields  us  upwards  of 
30,000,000  gallons,  ^vdiich,  could  we  avail  ourselves 
of,  the  15  per  cent,  here  indicated  would  give  us  a 
constant  delivery  of  50,000,000  gallons  per  day, 
and,  with  the  additional  ISyV^  s(|uai'e  miles  of  our 
unappropriated  sub-district,  a  further  increase  to 
61,000,000,  or  a  minimum  equal  to  40,000,000  gal- 
lons, irrespective  of  the  storage  reserve, — all  which 
may  be  wholly  procured  from  tlie  territory  lying 
above  the  line  of  Conduit  Extension.  This,  then, 
may  be  regarded  as  the  natural  and  available  quan- 
tity within  the  reach  of  our  works,  as  they  are  now 
located   and  constructed ;  and  I  have,  therefore. 


41 


directed  my  liKjuirics  almost  exclusively  to  tlie 
reliable  determination  oj'tlie  yield  ol'tliis  reiiion. 

But,  it  A\ill  be  ])(M'ceived  that  tlie  whole  district 
lying  Ix'tween  this  line  and  the  shore  of  Jamaica 
])ay  lias  not,  thus  far,  entered  into  my  estimate.  It 
must,  liowevei",  deliver  ])ro])ortionally  a  much  larger 
(quantity  than  any  other:  since,  in  addition  to  tlie 
regular  rain  ])recipitati()n  u])on  its  surface,  w  hich,  ot 
course,  would  er[ual  the  amount  per  square  mile 
assumed  for  the  main  district,  it  yields,  also,  all  the 
unestimated  surplus  that  may  have  come  down  to 
it  from  tlie  higher  grounds  Avhich  anc  liaxc  been 
considering.  I  have  attempted,  therefore,  to  ascer- 
tain this  important  increment,  in  a  general  way,  by 
noting  the  changes  in  the  s])ecific  gravity  of  watei* 
alono;  tlie  shore  of  the  bay  at  dilfereiit  states  of  the 
tide,  and  afterward  rouglily  computing  a  mean  j)er- 
centacje  for  the  daily  infusion  of  fresh  water  cominfr 
from  our  entire  drainage  district,  and  subse(piently 
deductino^  the  known  yield  of  the  streams. 

A  carefully  tested  hydrometei'  was  used  tbr  this 
j)Ui-])ose.  The  ivsult  of  these  observations  is  given 
in  the  table  (marked  II  )  in  the  A])pendix, — each 
recorded  exj>eriment,  it  ma\  be  remarked,  being  the 
average  of  a  nundx-i'  of  ti'iab. 

The  shore  edire  boundini:"  our  drainaL^-e  district 
has  a  leULi'th  of  rather  more  than   f<»ui'  niile<  on 


42 


Jamaica  bay,  and  about  three  and  one  half  on 
Hempstead  bay.  At  various  points  on  this  line  the 
several  streams  which  at  present  supply  our  works 
have  their  mouths.  Abandoning  now  any  attempt 
at  a  calculation  of  the  Hempstead  line,  upon  which 
no  experiment  has  been  made,  we  find  that  Jamaica 
bay  has  a  total  water  area  of  about  23^  square 
miles,  with  an  average  water  depth,  at  Ioav  tide,  of 
about  four  feet,  giving  us  2,995,110,400  cubic  feet 
of  water.  Estimating,  from  the  talde  of  observa- 
tions, the  fresh  water  infusion  to  be  10  per  cent,  of 
the  whole  quantity,  we  have  295,511,040  cubic  feet 
as  the  amount  in  store  in  the  whole  bay  at  low 
water,  when  the  springs  and  streams  are  discharging 
most  abundantly.  Assuming  one  fourth  of  this 
quantity  only  as  coming  from  our  supply  district, 
there  remains  7^,827,760  cubic  feet.  On  the  suppo- 
sition that  the  waters  of  the  l)ay  are  not  wholly 
renewed  oftener  than  thrice  per  month,  -J-^-  of  the 
above  quantity  would  give  us  the  whole  daily  fresh- 
water delivery,  equal  to  7,^82,770  cul)ic  feet.  The 
minimum  yield  of  the  streams  of  all  the  territory 
north  of  Conduit  Extension,  as  stated  in  the  early 
part  of  this  report,  is  22,848,760  gallons,  or 
2,860,920  cubic  feet ;  of  which,  however,  the  flow  of 
Rockville  and  Hempstead  Creeks,  with  their  tribu- 
taries, is  to  be  deducted,  since  they  empty  into 


43 


ni'iii])stea(l  l)a}', — leaving,  tlu'ivt'oiv,  l,r);)L\(iln  (111)10 
feet  to  ]>e  taken  from  tlie  whole  computed  discliarge 
into  Janiaira  ]>ay,  and  w  liich  \vill  tlicn  i)e  r),S,S0,766 
(•ul)ie  feet,  or  47,*ii^l>,000  irallons.  llw  wliolc  district 
comprised  between  the  (/ondnit  Kxtension  line  an<l 
the  shores  of  the  Lays  amounts  to  nearly  l<>yV"o- 
s(|uare  miles,  of  wliich,  discharging  into  Jamaica 
J^ay,  delivers  the  above  minimum  of  47,*2:21>,UOO 
gallons, — at  a  rate,  consequently,  of  4, U 7 1,400  gallons 
per  s(|uare  mile.  The  remaining  poi-tion  of  ()jVo 
s(piare  miles,  discharging  into  Hempstead  bay  under 
exactly  analogous  peculiarities,  Avould  aftbrd,  there- 
fore, at  the  same  calculation  per  scpiarc  mile,  a 
further  amount  of  34,402,088  gallons. 

Upon  collecting  all  these  above  quantities,  and 
addiuii  their  difterent  results,  Ave  reach  the  followinir 
summary  : — 


ll  1 

J.  F<»r  the  aN  iiil;il)Ir  water  (Idivciy  iiitn 
the  present  works,  as  aseertaiiied  )>v 
earel'iil  cau^^iiifj,  wc  have,  tor  

'2.  F<»r  (Iraiiiajre  of  surplus  Mater  into 
Jamaica  Vjay,  as  ascertained  l»y  Ily- 

\  1 

Pq. 
miles. 

! 

N.  Y.  gallons. 

73.64 
50 

1 

22,343,760 
47,221>,000 

1 

34,40-2,088 

For  drainajn^  of  sur[>lus  water  int(» 
Hempstead    hay,   \n  comparative 

1 
1 

T..tals  

lO.S. 97  1.760 

44 


It  may  very  properly  be  urged,  tliat  the  data 
upon  wliicli  items  Kos.  2  and  3  have  been  computed 
are  entirely  vague  and  insufficient,  and  would  prob- 
ably be  largely  affected  l^y  many  natiu'al  contin- 
gencies wliicli  have  not  been  investigated  or  alluded 
to.  It  may  ])e  seen,  however,  if  we  return  to  an 
examination  of  the  more  reliable  figures  gathered 
from  the  facts  relating  to  the  district  Avhich  we  have 
already  appropriated,  that  it  was  there  found  that  a 
loss  of  78  per  cent,  of  the  annual  ])recipitation  was 
very  satisfactorily  determined.  This  loss,  then,  car- 
rying out  that  computation,  would  anioimt  to 
79,218,828  gallons,  and,  added  to  the  quantity 
actually  gauged,  viz.,  22,348,760  gallons,  gives  us  a 
daily  delivery  of  101,562,588  gallons.  If,  also,  to 
this  be  added  the  same  rate  of  precipitation  upon 
the  shore  district,  amounting  to  23,345,400  gallons 
more,  Ave  have  a  grand  total  precipitation,  over 
the  whole  DOylo  s(juare  miles,  of  124,907,988  gal- 
h^ns'  equivalent, — allowing  us,  you  will  perceive, 
21,000,000  gallons  daily  surplus,  or  nearly  20  per 
cent.  al)ove  my  hydrometric  estimate,  which  ^ve 
may  credit  to  the  necessary  vegetable  waste,  and  to 
the  evaporation.  Hoav  this  evaporation  might  be 
lessened  ])y  careful  subsoil  drainage,'"'  and  thus  a 

*  It  seems  to  be  commonly  conceded  that  nearly  the  -whole  rain-fall, 
during  the  months  of  July,  August,  and  September,  is  evaporated  before 


still  further  n)ntril)uti()ii  to  tlic  rcsoinvcs  of  our 
su})])ly-l)asiu  secured,  1  do  not  ])ro])ose  to  iii([uir(', 
iny  object  luiviiig  l)een  simply  to  call  your  attention 
to  tlie  general  capacity  of  the  basin  under  circum- 
stances of  its  j)resent  natural  yield. 

But  it  is  wca'th  w  hih'  to  consider,  in  case  the 
city  ever  contemidates  an  extension  of  her  ^vorks, 
whether  some  way  could  not  he  devised  for  collect- 
ing and  securing  a  portion  of  the  great  waste  ^vhi(•h 
has  been  sliown  to  occur,  and  thus  avoid  the  larger 
outlay  likely  to  be  needed  in  the  purchase  and 
adaptation  of  new  territory  to  the  ])urposes  of 
increased  supply. 

In  view  of  such  a  necessity,  the  value  of  a 
thorous^h  and  continuous  series  of  observations  and 
experiments  becomes  very  apparent,  and  the  pro- 
priety of  instituting  some  system  of  this  kind  ^\  ill 
undonbtedlv  suofo'est  itself  to  vou. 

I  ha\-e  appended  tables  of  rain-fall  for  Fort 
Hamilton,  Fort  Colundms,  and  Flatbush,  with  ])ro- 
files  of  various  monthly  and  yearl}*  averages,  whose 
res])ective  lieadings  ^vill  suiliciently  ex])lain  them. 

I  havt^  not  thought  it  ])i'oper,  in  the  limited 
range  of  this  investigation,  to  submit  anv  facts 
relating  to  tlie  character  and  ([uality  of  tlie  water 

reathiiii;  tlu'  iiiulcricrouiul  stonigi' ;  tlie  spriiiijs  and  stream!*,  consequeuti y. 
(.lurinu:  tliis  time,  draw  wlu.lly  \\\n>u  tlie  reserve. 


46 


from  tlie  different  streams,  since  it  must  evidently 
be  considered  a  very  distinct  and  special  l)rancli  of 
inquiry. 

It  gives  me  great  pleasure  to  acknowledge  the 
important  assistance  of  Messrs.  Martin  &  Whitman 
in  the  surveys,  and  of  Mr.  Williams  in  the  accom- 
panying map. 

Very  truly, 

THEODOEE  WESTON. 


APPENDIX. 


V  P  P  E  N  D I  X  . 


[A.l 


EXPERTMENT>   MADE   TO   DETERMINE   AnSORIUNG  CAPACITT  OF  SAND 
AND  GRAVEL. 

.The  experiments  were  made  in  a  tifjhl  box,  rontnining  one  cubic 
foot,  the  box  being  first  filled  tvith  the  sand^  and  water  afterward 
added. 

No.  1.  Sand  loosely  thrown  in,  0.300  cub.  ft.  water. 

2.   0.350       "  " 

3.  "  "   0.310 

"    4.     "         "  "   0.325 

"    5.  '•  "   0.350 


0.  ••   0.37 


tamped  with  shovel.  0.270 

8.  "     rammed  very  closely,  0.230  •• 

9.  Coarse  sand,  loosely  thrown  in,    ,.0.320  " 

10.  "   0.32S 

Jl.      "   0.310 

12.  Sand  and  gnivel,  loosely  thrown  in,  0.2r»0 

13.  "  "  "  0.275       "  " 

11.  "  "  0.323  "  " 
15.     "              "          "          "         0  275       "  " 


50 


No.  16.  Grarel,  clear,  loosely  thrown  in,.  .  .  .0.360  cub.  ft.  water. 
"  17.  -        ...  .0.358 

"  18.  "  ....0.350 

"  19.  •  •  ....0.345 

"  20.      ^'  "  ....0.350 

"  21.  ...  .0.363 

22.  Broken  stone,  specification  size,*.  .  .0.520  " 

*  \iz.,  8  cubic  inches. 


51 


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J  A  M  AI  ( -  A ,  J II I  If  '^S  /// ,  I  .s:)0 . 

J.  P.  KiRKwooD,  Esq. 

Dear  Sir: — In  obedioiicc  to  your  ^\  ishes,  I  Iiave  hastily 
ondoavorcMl  to  ascertain  tli(^  additional  flow  <•!' water  l)etween  our 
Valley-Stream  Reservoir  and  Watts'  Pond,  next  helow  on  the 
same  stream  ;  and  that,  also,  between  Brookfield  Reservoir  and 
Conselyea's  Pond,  next  below. 

Of  the  first  ease,  I  am  sorry  to  say  that,  owing  to  the  irregular 
and  capricious  use  of  water  in  the  mills  above  on  this  stream,  I 
found  it  impossible  to  obtain  any  reliable  gaugings  in  the  short 
time  at  my  disposal,  and  have,  therefore,  thought  it  best  to  omit 
the  record. 

F()r  the  latter,  however,  the  sul)ioined  table  will  indicate  to 
you  the  comparative  increase  of  which  you  wished  to  assure 
yourself;  the  gaugings  were  taken  under  favoralde  circumstances 
of  flow,  and,  as  you  will  perceive,  show  a  very  uniform  register. 

Brookfield  (Simonson's)  Stream  receives  no  noticeable  acces- 
sion tV<»m  any  bi-ancli  or  ti-ibutaiw  ])etween  the  tw(»  ponds  undci- 
observation  ;  but  the  whole  intervening  gi-ound  on  either  side  of 
it  is  full  of  springs,  which  dischai-ge  into  the  current  very  freely. 
The  distance  from  Brookfield  Reservoir  to  Conselyea's  Pond  is 
r),'2()0  feet. 

Tilt'  luctliod  of  gauging  was  as  t'oHnws  :  At  I>rookfirld  Kcscr- 
voir  our  present  weir  of  masonry  was  used,  and  the  de{)tli  ol'd.iu 
on  the  (jver-fall  measurc(l  a  few  feet  back  in  still  watci-,  l»y  a 
hook-gauge,  apitTn'tl  to  a  lixcd  graduated  rotl.  This  wcii-  has  a 
width  of  I  J  ,Y-  feet,  an<l,  as  you  will  sec  by  the  aniu-.\ed  table. 


56 


the  depth  of  flow  over  it  did  not  reach  two  inches  ;  on  applying 
Mr,  Francis'  formula,  therefore,  to  the  calculations,  inasmuch  as 
its  conditions  were  not  completely  filled,  I  have  modified  it 
slightly  to  suit  this  particular  case.  No  perceptible  contraction 
occurring,  I  have  neglected  the  deduction  for  effective  length, 
0.2  and  corrected  the  constant  3.33, — the  formula,  as  used, 
standing  thus  : —  _^ 

At  Conselyea's,  however,  a  weir  Avas  insertedWiT  the  mill- 
sluice,  following  closely  the  form  of  construction  recommended 
by  Mr.  Francis.  The  width  wa^|;^de  2y/o  feet,  the  height  of 
fall  nearly  four  feet,  the  streani^uniformly  flowing  more  than 
eight  inches  deep  over  it, — securing  us,  consequently,  a  very 
accurate  application  of  the  regular  formula, 

^=3.33|^^X^-0.2  H). 

The  gaugings  were  made  simultaneously  at  both  ponds  every 
three  hours,  on  the  26th,  and  every  hour,  from  9  A.  M.  to  6  P.  M., 
on  the  2Tth, — the  full  flow  of  the  stream  being  reached  about 
2  P.  M.  of  the  second  day,  and  continuing  quite  regular  up  to 
the  time  our  observations  ceased. 

The  increment,  vou  will  discover,  amounts  to* about  one  and 
a  half  millions  of  gallons, — a  very  important  and  suggestive 
diflerence. 

In  the  case  of  Valley  Stream,  1  should  l)e  glad  to  repeat  my 
observations  with  more  care,  and  sufficiently  long  to  ascertain 
the  analogous  increase  which  comes  into  that  stream  below  our 
reservoir. 

I  remain,  very  respectfully. 

Your  servant, 

THEODORE  WESTON. 


59 
[1^1 

Jamaica,  Aifr/usl  23f/,  1859. 

Mt/  Dear  Sir  : — Since  tlic  date  <»f*  my  last  stateiiiciit  to  yoii 
concerning  the  relative  increase  <»r  How  Ijclweeii  the  ^'alley- 
Strcam  Reservoir  aiicl  AVatts'  Pond,  l)elo\v,  on  tlie  same  stream, 
I  have  regauged  tlic  delivery  at  hotli  these  ]>oints  with  some  care, 
the  resnlt  ofwliicli  is  apjx'iided  in  the  accompanying  record. 

Having  etrectuaily  removed  all  causes  of  irregularity  that 
were  discoverable,  I  continued  the  gaugings  for  some  time  after  a 
uniform  flow  was  reached,  in  order  to  assure  myself,  hcyond  a 
doubt,  of  a  correct  determination  of  the  difference  sought  to  be 
established. 

The  weirs  used  at  the  j^resent  trial  were  constructed  some- 
what diflx'rently  from  those  first  emi)loyed. 

At  Valley-Stream  Reservoir,  the  present  over-fall  of  nnisoni-y 
was  narrowed  by  a  breast-board,  in  which  a  weir,  7  feet  wide, 
was  cut  out.  It  was  placed  on  the  outer  edge  of  the  masonry, 
and  had  a  height  of  yYo  Jtl^ove  it.  The  arrangement  will  be 
undei'stood  fi-om  Figs.  1  and  '2. 


Reservoir  Wtpler  sur^force 


60 


The  water  was  retained  in  the  reservoir  until  its  head  had 
reached  foVo  ^t-  on  the  weir, — at  which  point,  as  will  be  seen 
by  the  table,  our  observations  commenced. 

At  AYatts'  Pond,  below,  the  weir  was  placed  in  a  rectangular 
sluice-way  which  belongs  to  the  mill  on  that  pond.  This  sluice- 
way Avas  about  15  feet  long,  with  a  width  of  SyV^^^  feet.  The 
over-fall  bar  was  made  the  entire  width  of  the  sluice-way,  and 
inserted  about  3  feet  from  its  lower  end. 

Our  observations  began  at  11  A.  M.,  August  4th,  and  ended 
at  6  P.  M.,  August  8th.  From  August  4th  until  6  A.  M.  of  the 
8th,  the  gaugings  were  noted  every  two  hours ;  and  from  6  A.M. 
to  6  P.  M.,  on  the  8th,  they  were  registered  every  hour.  As  in 
the  former  trial,  a  hook-gauge  was  used,  and  readings  taken 
simultaneously  at  both  ponds. 

The  flow,  it  will  be  noticed,  increased  quite  uniformly  up  to 
2  P.  M.,  August  5th,  at  which  time  a  sudden  rise  occurred  in  the 
reservoir,  owing  to  the  discharge  of  the  waters  in  the  mill-ponds 
above, — which,  however,  from  this  date  until  the  conclusion  of 
our  gaugings,  were  placed  under  our  control.  The  natural  deliv- 
ery of  the  stream  seems  to  have  been  reached  about  12  M., 
August  8th,  the  observations  showing  very  little  variation  after 
that  hour. 


fii  a|t[)lyiii  r  tlio  Inriniilas  for  calciilarn I  liavc  considered 
that  neither  weir  followed  precisely  tlic  conditions  of  construction 
required  in  the  correct  use  of  any  of  the  ordinary  forms.  I  have, 
therefore,  adopted  one  most  applicalde  to  bot.li  weirs,  correcting 
thi'ni  by  a  moan  coefiivient  suited  more  particulai-ly  to  each 
case. 

In  Ctistel's  experiments,  at  Toulouse,  a  sluice  feet  long 

and  '2y*oVo  ^^^^  wide  was  used,  autl  a  \\v\r  of  etpial  width  placed 
at  the  lower  end,  with  a  deplh,  from  the  crest  of  the  over-fall  to 
the  ])ottom  of  the  sluice-way,  of  ft.     Witli  a  head  <.f 

ft.,  or  a  little  less  than  one  half  the  lieight  of  the  over-fall  bar,  he 
ol)tained  a  coefficient  0.602;  and,  upon  either  increasing  or 
diminishing  this  head,  very  little  variation  followed. 

The  circumstances  of  this  experiment  are  so  closely  analogous 
to  our  own  case  at  Watts'  Pond,  that  1  have  adopted  the  coeffi- 
cient so  obtained,  and  applied  it  in  the  formula, 

Q=^.Soj)imy/ll';  where 

(^:=Quantity,  in  cul)ic  feet,  discharged  per  second. 

5 .35  =  J  ^/f/ h = Thcoret i cal  d ischa rgc . 

/=Width  of  \Vcir  =  3,V^^5  ft. 

m  =  Correction  for  discharge=0.665. 

At  Valley -Sti-eam  luvservoir  I  have  used  the  same  form,  but 
/  in  this  case  =7  ft.,  and  iii=OA\00  (wITu-h  includes  err(u*  for  con- 
traction). This  valu(^  of///,  is  dcii\cd  fmm  the  results  of  Biack- 
welTs  iiivestigatinns  <ni  the  Avmi  (anal.  The  width  (.('  his  wi'ir 
was  (»  f('rt,()Ui'  (twii  bciiiif  7  feet.  In  his  case,  the  dcjUli  of  water, 
for  sonu-  little  distance  hack  from  the  o\(M--lall,  was   reduced  to 

18@20  inches,  by  a  suhmerged  course  of  nuisonry.     In  our  own 
9 


we  have  a  corresponding  depth  of  from  13@18  inches  for  a  dis- 
tance of  4'  0"  back.  He  phiced  his  over-fall  on  the  outer  line  of 
the  dam  ;  the  position  of  our  own  is  the  same. 

In  case  closer  accuracy  is  essential,  from  the  data  now  in  our 
possession  new  coefficients  could  be  calculated  for  each  variable 
head  ;  the  same  relative  difference,  however,  would  be  preserved 
in  the  flow  at  both  points, — which  I  have  regarded  as  the  more 
special  object  of  our  investigations. 

The  circumstances  under  which  the  gaugings  here  presented 
were  made  have  been  so  favorable  that  I  feel  great  confidence  in 
offering  them  to  you  as  reliable  and  sufficient. 

Very  faithfully, 

THEODORE  WESTON. 

Jas.  p.  Kirkwood,  Esq., 

Ch.  Emir.  B.  W.  W. 


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Obseryatioxs  ox  the  Specific  Gravity  of  Water  aloxo  the 

SHORE  OF  Ja^EAICA  BaY. 


Green's  Standard  Hydrometer  vsed.    Distilled  Water  at  C0°  Fahr.  =  1000. 


DATE. 

LOCALITY. 

jiign 
Tide. 

Ebb 
Tide. 

Tow 
Tide. 

Flood 
Tide. 

Tempera- 
ture of 
Water. 

Wind. 



1860. 





Sept.  24. 

Mouth  of  Jamaica  Creek  (at  D  on  map).  .  . 

1016 

1014 

>-oO 
(  O 

S.  E. 

"  25. 

1017 

1012 

bo 

N.W. 

"  26. 

1010 

10035 

0.:5 

Calm. 

"  27. 

1015 

1013 

Sept.  24. 

About  90(»  feet  fi-om  mouth  (at  C  on  map). 

<<           (i  a 

1015 

1014 

/TOO 

/  o 

S.  E. 

"  25. 

1010 

DO 

N.W. 

"  26 

<(           i(  <( 

1001 

Do 

Calm. 

"  27. 

<<           ((  <i 

1007 

OV 

Sept.  24. 

1016 

iv 

S.  E. 

"  25. 

1006 

uo 

N.AV. 

"  26 

1000} 

DO 

Calm. 

"  27. 

1008 

1003^ 

nQ° 
OxJ 

,  Sept.  24. 

1014 

i  6 

S.  E. 

"  25. 

1008 

bo 

N.W. 

"  26. 



1002^ 

1000 

DO 

Calm. 

"  27. 

"  "   

1005^ 

1003i 

" 

Sept.  24. 

1017 

70° 

S.  E. 

\     "  25 

1018 

70° 

N.W. 

i     "  26. 

"  "   

1017 

63° 

Calm. 

i    "  27. 

101  Si 

62° 

Sept.  24. 

Mouth  of  Spi'ingfielil  Creek  (at  F  on  map). 

lol4i 

73° 

S.  E. 

"  25. 

((                   t(  a 

1016 

69° 

N.  W. 

"  26! 

1012 

69° 

Calm. 

>    "  27. 

1009 

69° 

Sept.  24. 

Moutli  of  Long  XtH'k  Creek  (at  G  on  map). 

1017 

S.  E. 

"  2.5. 

1017 

N.W. 

"  26. 

1015 

Calm. 

Sept.  26. 

1017 

1015 

1017 

1016 

Sept.  27. 

1019 

64° 

1020 

64° 

'(  <i 

"           "       opposite  Sea-siJe  House. 

10204 

63° 

u 

i»  It 

1020 

1020 

62° 

(<  <t 

1019 

62° 

Sea  v'<(Ur  from  outside  Rockaway  Beach. .  . 

1025 

1025 

67° 

26 

Water  from  Salt  Creek,  running  into  main 

1 

1017 

66° 

WEATHER. 

Sept.  24.— WinJy  from  the  S.  E. 
"    25.—    "  "  N.W. 

"  26.— Calm.  Unusually  low  tide  in  Bay,  at  llh.  30m.  A.  M. 
"    27.—    "        Usual  low  water  at  12  M.' 


